For A it’ll be: UAG
(Explanation: Adenine pairs with uracil in mRNA)
For B it’ll be: CAU
(Explanation: Guanine pairs with cytosine, Uracil pairs with adenine and adenine pairs with Uracil once again.)
For C it’ll be: AUC
(Explanation: Uracil pairs with adenine, same for the second, and guanine pairs with cytosine.)
